Scripture warns us, indeed Jesus did, against judging others. I think this works on at least two levels. We’re most definitely not to judge another in the sense of any final judgment which only God can render. And we’re to be wary of jumping in to correct problems in others unless we are ruthlessly doing the same first to ourselves.
Much of the time for us it’s better just not to make any judgment of others at all. Scripture does tell us that we will know people’s heart by their fruit, meaning works and life. Not in some complete, final, or in/out sense, but something of what people have in their hearts at the time. And we in Jesus not only need God to search our own hearts so we can understand whatever might be wrong in them, but we need the Spirit’s searching as well in order to try to help anyone else. But again we need to be slow to undertake any such endeavor. In fact it’s best for a time that we refuse to judge another at all, instead being sure that we ourselves have our own house in order.
I think we are best most often to refuse to judge another because it really takes time to begin to discern all the good along with what might be wrong in another. If our attention is on someone, it may be a problem we have in our own hearts, as well as possibly a problem they have. Or it may be something evident to us about them, even if we can’t put our finger on it at the time. But even if we think we can, we need to step back and slow down and pray. And be slow to think such and such about a person. We need to learn to “read” another person and maybe something of what we can see of their life with love. And we need to remember as well that love covers over a multitude of sins. We need that from others ourselves.
In the end we’re all in this together in Jesus, and together in this for all. God makes it so that we do need each other in Jesus. All mediated by Jesus, but for and through us to each other, as well as in regard to and for the benefit of the world.